Settling apparatus



Oct. 30, 1934. J. M. MITCHELL 1,979,168

I SETTLING APPARATUS Filed Oct. 14, 1952 3 Sheets-Sheet l Oct. 30, 1934. J, M WT HELL 1,979,168

SETTLING APPARATUS Filed Oct. 14, 1932 3 Sheets-Sheet 2 @HIMMW Oct. 30, 1934. J MlTCHELL 1,979,168

SETTLING APPARATUS Filed Oct. 14, 1932 5 Sheets-Sheet 3 1 MMTZW Patented Qct. so, 1934 I 1,97%];68

STTES PAEIEN'I" GFFKE WM 1: ammmwm SETTLING APPARATUS James ltiacdonald Mitchell, Old Lyme, Conn.

Application @ctober 14, 1332, Serial No. 837,847

6 Claims. (01. Mil-54) This invention relates to settling apparatus for ture is particularly desirable in tanks which are separating solid materials such as sand, gravel, to be used for settling fine and light materials minerals and the like from liquids. which will not settle readily under turbulent con- In this type of device a tank is utilized having clitions in the tank such as may well be brought :f a valve discharge located in or near its bottom about by maintaining the material discharge open 60 through which the solid materials are discharged for any considerable length of time. Since there after settling out of the liquid under the force will be no flow between the column and the tank of gravity. and hence no rising currents in the periods when The present invention has for its essential obliquid from the independent supply is not enter- 10 ject the provision of automatic means for coning the column, solid materials will settle in the 65 trolling the discharge of the solid materials which tank and as the level thereof rises pack against is of simple and efficient construction, and which the end of the column to seal the same. Also, may be readily installed in settling tanks of all by discharging the settled materials in small sizes and shapes with equal facility. The proquantities at recurrent intervals instead of all at posed control means is of such character that it one time turbulence in the tank will be minimized 70 may be readily installed in tanks originally built and the materials allowed to settle in relatively with a manually controlled discharge for settled quiet liquid. materials. I have in the accompanying drawings illus- According to lily-invention an upstanding tubutrated several embodiments of my automatic dislar member isprovided having its lower end opencharge control for settling apparatus, together 75 ing into the settling tank above the discharge with several forms of devices which may be utivalve. Such element is intended to receive a lized to render the same periodically operative. liquid column and will extend somewhat above It is to be understood that the drawings are illusthe normal liquid level of the tank. Being in trative merely and that the invention is capable communication at the tank at its lower end the or a co1'1siderable degree of modification and 80 level of liquid in the tubular member will be deequivalency as will be readily apparent to those termined by conditions in the tank, it being arskilled in the art. In the drawings: ranged so that as solid materials settle in the Fig. 1 is a sectional elevation of one type of tank the lower end of the tubular member will settling apparatus with one embodiment of my be closed thereby to prevent the interilow of liquid automatic control means applied thereto; 85 between the tank and the liquid column. The Fig. 2 is a view similar to Fig. 1 illustrating upper end of the tubular member will receive a particularly a second embodiment of my autosupply of liquid, such as water, from an independmat-i0 control means; ent source of supply. As long as the lower end Fig. 3 is a fragmentary view corresponding to thereof is open the level of the liquid column will Fig. 1 showing a modification;

be the same as that in the tank, but as soon as Fig. l illustrates one type of device which may settled materials close theend the independent be used in association with the automatic conliquid supply will cause the level torise. Such trol means shown in Figs. 1 and 2 to cause the change in level of the liquid column, operating same to operate intermittently; and, 40 through a float or counter-balanced Water box Fig. 5 shows a second type of periodic mecha- 95 is utilized to open and close the discharge valve nisrn serving the same purpose as the device of in accordance with fluctuations in level or" the Fig. 4. settled materials in the tank. In order that such In the drawings wherein like reference characcontrol means may be quickly responsive to ters indicate like parts the numeral 10 indicates changes in condition the tubular member is prefone form of settling tank into which mixed solids 199 erably of small diameter so that the changes in and liquids, such for example as sand and water, level of the liquid therein may be considerable and are introduced from a source of supply such as rapidly brought about. the pipe 11. Near the top of the tank is an over- The invention also contemplates the provision flow 12 into which the excess liquid from the tank of periodically operating means in association passes. The solid materials coming in from the 1f with the automatic discharge controlwhereby the supply will gradually settle through the liquid to latter, when settled materials have risen to a level the bottom of the tank because of their greater to render the same operative, will operateinter- Weight. A discharge port to permit the withmittently according to a desired time frequency drawal of the settled materials is located in or to open and close the discharge valve. Thisfeanear the bottom of the tank, such for example as the port 13. The discharge port is controlled by a valve 14, the operation of which will be determined by the control mechanism hereafter to be described. Such valve may be conveniently supported on the pivotal arm 15 carrying a counter weight 16 intended to maintain the valve normally closed.

According to'the embodiment of my invention shown in Fig. l the automatic control mechanism for the discharge valve will include an upstanding tubular member 17, the lower end 18 of which opens into the tank some distance above the discharge valve. Such pipe may be located wholly within the tank or, as shown in the figure, extend outside the tank for the major portion of its length. Such tubular member will extend above the normal liquid level in the tank as de- .termined by the liquid overflow 12 so as to permit the level of the liquid column to rise above the normal level of the liquid in the tank. As long as the level of settled materials in the bottom of the tank is below the end 18 of the tubular member the level of liquid in the latter will be the same as that in the tank. As the settled materials rise the tubular member will be cut off from the tank so as to prevent the interfiow of liquid therebetween.

The upper end of the tubular member will receive liquid from an independent supply which will normally flow through the column into the tank, but which when the member is cut on from the tank will cause a rise in the level of the liquid therein. The upper end of the tubular member may be provided with a funnel 19 into which liquid from an independent supply pipe 20 may be fed, the latter preferably being provided with a control valve 21 so that the rapidity of the fiow may be controlled at will. Associated with the tubular member above the normal liquid level in the tank is a chamber 22 in which is located a float supported on a pivotal arm 23.

With the arrangement just described liquid will rise in the column when materials have settled to close the lower end 18 of the tubular member by reason of the continuous flow from the independent supply 20. As the liquid level rises in the chamber 22 the fioat will be raised. To prevent the float chamber from overflowing the tubular member is provided with an overflow pipe 24 at a height level with the top of the float chamber. Thus the liquid in the column will be prevented-from rising so as to cause an overflow through the float chamber or the funnel 19.

The control mechanism just described will according to the embodiment shown in Fig. 1 operate through an electrical mechanism which will cause actuation of the discharge valve. To this end the float controlled arm 23 may constitute an electric circuit breaker controlling an electric actuating device such as a solenoid 25 operating through an arm 26 to open and close the valve 14. When the arm 23 is in horizontal position, as

shown, the actuator circuit will be open. As the liquid rises in the tubular member and in the float chamber such arm will be raised to close the circuit and cause the actuator to open the discharge valve. As soon as the level of settled materials diminishes to open the lower end 18 of the tubular member the level of liquid in the column and in the fioat chamber will drop and cause the arm 23 to open the actuator circuit so that the discharge valve will be closed by the counterweight 16. Of course whether the actuator is arranged to open or close the discharge valve when its circuit is closed is a matter of choice.

' was maintained constant.

Instead of utilizing my invention in connection with an electrically actuated discharge valve controlling mechanism, the same may operate directly through mechanical means such as shown in Fig. 2. In this embodiment a tubular member 27 is provided having its lower end 28 in communication with the settling tank above the discharge 13. Located externally of the tank in general horizontal alinement with the normal liquid level therein is a box 29 communicating at its lower end with the tubular member through a flexible hose connection 30. Into such box feeds an independent liquid supply 31. The rise and fall of liquid in the tubular member and in the box under variations in level of the settled material in the tank will be the same as that heretofore described in connection with the embodiment of Fig. 1. In order, however, that the change in level of liquid in the box 29 may be rapid and correspond to change in condition in the tank the independent supply should be more rapid and to this end the supply pipe 31 is preferably of larger diameter than that of the supply pipe 20 of Fig. 1.

The box 29 is supported by a cable 32 running over a pulley 33 and connecting at its other end with the discharge valve arm 15. As the liquid rises in the box 29 the weight thereof will overcome that of the counter-weight 16 and cause the box to drop and open the discharge valve, this being possible by reason of the flexible connection between the box and the tubular member 27. Near the top of the box 29 is provided an overflow pipe 34 feeding into the settling tank. When the settled materials have been discharged in sufficient quantity to open the lower end of the tubular member the level in the box 29 will drop to that in the settling tank and thereupon the box will be raised by the counter-weight 16 and the discharge valve will be closed.

In either of the embodiments shown in Figs. 1 and 2, as above described, the level of the liquid in the tubular member and the operation of the discharge valve will be determined solely by the level of the settled materials in the tank with reference to the lo-werend of the tubular member. This was so by reason of the fact that the independent supply of liquid to the tubular member When and as long as settled materials seal the end of the tubular memher the level of the liquid column should be such as to maintain the discharge valve open. It may be desirable when the apparatus is to be used in connection with fine or light materials, such, for example, as graphite or very fine sand, which will not settle readily under continued turbulent conditions in the tank, to maintain the discharge valve open for only relatively short periods regardless of the level of the settled materials in the tank. To this end I propose to provide regulatory means which will supplement the rise and fall in level of the settled materials in the tank in determining the opening and closing of the material discharge valve with a view of making the rise and fall in level of the liquid column occur at predetermined time intervals. Such arrangement will also prevent the fiow of liquid between the column and tank during any selected intervals in which no liquid from the supply is fed to the column and thus provide quiet liquid in the tank at such times which is most conducive to settling of materials.

The regulatory mechanism will operate through the independent liquid supply to cause liquid to be fed tothe column intermittently instead of continuously. Such an arrangement will not of course affect the level of liquid in the tubular member as long as the lower end thereof is not sealed by settled materials since there will then be a continuous flow of liquidfrom the tubular member into the tank during the periods when liquid from the supply is fed to the column. When settled materials rise in the tank the intermittent feed of liquid to the tubular member from the independent supply will regulate the level of the liquid therein and thus determine the opening and closingof the discharge valve.

I have in Figs. 4 and 5 shown two forms of devices which may be utilized to cause an intermittent flow from the independent supply to the liquid column of the embodiments of my invention' shown in Figs. 1 and 2.

In Fig. 4 I have shown a so-called diamond box having two compartments 40 and 41 pivotally supported at the point 42 under an independent source of liquid supply comprising the pipe 43. As will be observed, the arrangement is such that liquid will flow to one of the compartments of the box which then because'of the increased weight will tip to discharge the liquid, thereby causing the second compartment to be brought under the source of supply in turn to be filled, tipped and discharged. The compartments 40 and 41 of the diamond box will discharge respectively into chambers 44 and 45 which preferably are provided with springs 46 and47 to cushion the movement of the box. The chambers 44 and 45 are provided with discharge pipes 48 and 49 which feed to a pipe 50 connecting with the tubular member of my invention. The device is shown as applied to the embodiment of Fig. 1, the pipe 50 connecting with the tubular member 17 through a sleeve 51 which enables the height of the periodic liquid feed mechanism to be adjusted vertically with respect to the tubular member and the tank. With the device as just described liquid will be fed to the tubular member intermittently and periodically first from the compartment 40 of the diamond box through the chamber 44 and pipe 48, and then from the compartment 41 which discharges into the chamber 45 and through the pipe 49. The frequency of operation of the device can be readily determined by the size of the compartments 40 and 41 of the diamond box and the rate of flow of liquid thereto through the independent supply pipe 43. The larger the diamond box the greater the length of time required for the respective compartments thereof to be filled and discharged. It may be desirable to provide a valve 52 in association with the supply pipe 43 to regulate the rate of flow'of the liquid.

When settling certain types of material it may be found desirable to cut down. materially the feed of liquid to the tubular member. To this end one of the feeds of one of the compartments of the diamond box may be withheld from the tubular member. Thus, as shown in Fig. 4, the feed from the compartment 40 of the diamond box may be rendered inoperative by providing the pipe 48 with a two-way valve 53 connecting with a waste pipe 54. When the valve is turned in one direction the feed through the pipe 43 will pass through the pipe 50 into the tubular member, and when turned in the other direction will discharge through the pipe 54. Under the latter circumstances the tubular member 1'? will be fed intermittently only from the chamber 41 of the diamond box. As a further means of control it may be desirable to provide a valve 55 in the pipe 49 so that the'rate of flow from the compartment 41 to the tubular member may be cut down.

With the arrangement described it will be possible to periodically regulate the level of liquid in the tubular member, and hence the operation of the discharge valve of any desired time interval within a range, more or less, of thirty seconds to twenty minutes when both of the cornpartments 40 and 41 of the diamond box are utilized. The frequency of operation may be cut in half by rendering one of the compartments of the diamond box inoperative so that the operating interval will range fromv sixty seconds to twenty minutes.

As shown in Fig. 5 the time control for the feed through the liquid column may comprise a valve 56 on the independent liquid supply pipe 20, the same being opened and closed periodically by a clock mechanism 57. The latter mechanism is provided with a rotating arm 58 which operates through the forked arm 59. The latter connects with the valve by lever 60 and may be conveniently supported by a bracket 61. The rotating arm 59 of the clock will first bear against the portions 62 of the forked arm moving the same to the right, say, to open the valve, and then later will bear against the portion 63 of the arm to move the same to the left to close the valve. The time of feed of liquid will be determined by the speed of rotation of the arm 58 of the clock.

Under some conditions where the periodic feed of liquid to the column is utilized it may be found desirable to take positive measures to insure the sealing of the lower end of the tubular member of my automatic control means when the level of the settled material rises to a point where the discharge valve should open. Where the apparatus is to be used to settle very light materials it may be that the flow of liquid into the tank from the tubular member may be sufficient to prevent the light materials from buildin up around and properly sealing the end 18 of the tubular member. Again where the apparatus is to be used for settling relatively coarse materials there may be difliculty in eifecting a perfect seal of the tubular member such as is necessary to cause the level of the liquid in the tubular member to rise in such manner as to operate the discharge valve controlling mechanism. Under these circumstances it is advisable to provide the end of the tubular member in the embodiments of my invention shown in Figs. 1 and 2 with a suitable valve against which the settled materials will bear to efiect a seal of the tubular member. I have in Fig. 3 shown a vave mechanism as applied to the apparatus of Fig. 1, the same comprising a flap valve 35 hinged on a bracket 36 adjacent the end of the tubular member. The valve is provided with a weighted arm 37 tending to hold the valve closed, the balance, however, being such that the valve will be held normally open by the weight and flow of the liquid through the tubular member through the independent source of supply. As materials settle in the tank they will bear against the side of the valve, and even though they be light will, in cooperation with the weighted arm 37, cause the valve to close and seal the end of the tubular member. After the discharge valve has been opened and the level of the settled material falls below that of the valve It will be seen from the above description and 15g the drawings that I have provided a simple and practical mechanism which may be installed at relatively small cost in any type of settling tank for the automatic control of the discharge therefrom. Any manually operated settling tank may without difiiculty be made automatically operative by the use of a few simple pipe fittings and auxiliary mechanism such as shown. My invention also provides means whereby the operation of a settling tank may be automatically controlled according to any desired time interval so that the same may be suitable for use in settling a great numb-er of solid materials oi various sizes and difierent weights.

It will be understood that the embodiments of my invention shown and described are merely illustrative and that I do not intend tobe limited in the practice of my invention other than may be required by the scope of the appended claims.

Iclaim:

1. An apparatus for settling solids out of liquids, comprising a tank having a liquid overflow and, at its lower end a discharge for settled material controlled by a valve, and an automatic control for the discharge valve including a pipe located outside the tank and communicating therewith at the lower end of the tank and extending upwardly above the normal liquid level in the tank said pipe supporting a liquid column, and being adapted to be cut off from the tank by the rise of settled material therein, the liquid column having a source of supply independent of the tank which will cause the level thereof to rise in the pipe above the liquid level in the tank as the tubular member is obstructed by settled material, an overflow in the pipe located above the normal liquid level in the tank to prevent the level of the liquid column from rising abnormally, and actuating means for the discharge valve controlled by changes in level of the liquid column.

2. An apparatus for settling solids out of liquids, comprisinga tank having a liquid overflow and, at its lower end a discharge for settled materials controlled by a valve, actuating means for the discharge valve, and an automatic control for the valve actuating means including a pipe supporting a liquid column located externally of the tank communicating at its lower end with the tank and adapted to be cut on therefrom by the rise of settled materials in the tank, an independent source of liquid supply feeding the liquid column and causing the level thereof to rise when the pipe is obstructed by settled materials, a movably supported chamber extending above the normal liquid level in the tank connecting with the pipe and adapted to receive and be depressed by the weight of liquid upon rise in level of the liquid column, and connecting means between the chamber and the valve actuating means.

3. An apparatus for settling solids out of liquids, comprising a tank having a liquid overflow and, at its lower end a discharge for settled materials controlled by a valve, a tubular member supporting a liquid column opening at its lower end into the tank at a point above the discharge valve, and extending upwardly above the normal liquid level in the tank, the lower end of the tubular member being provided with a valve adapted to be closed by pressure thereagainst of settled materials as the level thereof rises in the tank to seal the tubular member, an independent liquid supply feeding the tubular member and adapted to cause the level of the liquid column to rise when the tubular member is sealed from the tank, and actuating means for the discharge valve of the tank controlled by the changes in level of the liquid column.

4. An apparatus for separating solids out of liquids, comprising a tank having a liquid overflow and, at its lower end a discharge for settled material controlled by a valve, a liquid column communicating at its lower end with the tank at a point above the discharge valve and adapted to be cut oil therefrom by the rise ofsettled material, a liquid supply pipe communicating with said column and adapted to cause the level thereof to rise when the column is obstructed by settled material, a valve in the supply pipe, and automatic means periodically operative to open and close the supply valve to feed liquid from the independent source intermittently to the liquid column, and actuating means for the discharge valve of the tank controlled by changes in level of the liquid column.

5. An apparatus for separating solids out of liquids, comprising a tank having a liquid overflow and, at its lower end a discharge for settled material controlled by a valve, a liquid column communicating at its lower end with the tank at a point above the discharge valve and adapted to be cut off therefrom by the rise of settled material, said column having an independent source of liquid supply which will cause the level thereof to rise when the column is obstructed by settled material, a time-controlled valve regulating the feed of liquid from the independent source to the liquid column, and actuating means for the discharge valve of the tank controlled by changes in level of the liquid column.

6. An apparatus for separating solids out of liquids, comprising a tank having a liquid overflow and, at its lower end a discharge for settled material controlled by a valve, a liquid column communicating at its lower end with the tank at a point above the discharge valve and adapted to be cut off therefrom by the rise of settled material, said column having an independent source of liquid supply which will cause the level thereof to rise when the column is obstructed by settled 'material, a pivotally supported box having a plurality of compartments adapted to alternately receive and discharge liquid from the independent source, means for conducting liquid discharged byv the compartments of the box to the liquid column, and actuating means for the discharge valve of the tank controlled by changes in level of the liquid column.

JAMES MACDONALD MITCHELL. 

